In uninterruptible power supply systems, a DC/DC converter is typically disposed between the DC bus and a secondary power source, such as a battery. Upon detecting a failure in the primary power source, the DC/DC converter switches from supplying power to the battery over to supplying power to the inverter. Conventional techniques for detecting a failure in the primary power source involve measuring the source voltage. Such techniques may falsely detect a failure during the occurrence of a surge or sag in the source voltage. Additionally, relying solely on the source voltage will not detect a failure of the rectifier.
Therefore, it is desirable to develop an improved technique for detecting a failing rectifier or rectifier source. This section provides background information related to the present disclosure which is not necessarily prior art.